Jean-Pierre Pelage

Background: Transarterial embolization (TAE) is increasingly used across a broad spectrum of musculoskeletal conditions, ranging from established hemostatic and tumor-related indications to emerging pain-directed procedures for degenerative joint disease and chronic inflammatory tendinopathies. Because these applications differ substantially in clinical maturity, methodological quality, durability of outcomes, and comparative evidence, an indication-stratified synthesis is needed. Main body: This narrative review summarizes technical principles, vascular anatomy considerations, embolic agent selection, clinical indications, and evidence maturity in musculoskeletal TAE. Hemostatic and selected tumor-related applications are established components of multidisciplinary care, whereas pain-directed embolization, including Genicular artery embolization for knee osteoarthritis and embolization for tendinopathies, is generally performed as a stand-alone minimally invasive procedure targeting pathological neovascularity. Current evidence remains heterogeneous, with variable study designs, follow-up, endpoints, and definitions of technical and clinical success. Conclusions: Musculoskeletal TAE is an expanding field with established, intermediate, and exploratory indications. Its evidence base is strongest for hemostatic and selected tumor-related applications, whereas stand-alone pain-directed embolization requires careful patient selection, standardized outcome assessment, and further comparative trials to define durability and clinical value.

Purpose To systematically review the available evidence on the feasibility, safety, and clinical effectiveness of percutaneous sclerotherapy using radiopaque gelified ethanol (RGE, Discogel®) for bone lesions. Methods A systematic search of MEDLINE, Embase, Web of Science, and Cochrane CENTRAL was performed. Primary studies reporting clinical, technical, and safety outcomes following RGE sclerotherapy for bone lesions were included. Data on patient characteristics, lesion type, procedural details, and outcomes were extracted and synthesized descriptively. Results Six retrospective studies involving 55 patients (mean age 22.2 ± 20.4 years; range 3–65; 26 females) with 56 lesions and 119 procedures were included (mean 2.16 procedures per patient). Aneurysmal bone cysts (80%) and aggressive vertebral hemangiomas (18%) were the main indications. Technical success was reported in 100% of procedures. Pain outcomes were available for 28 patients, with complete resolution in 64.3% (18/28), partial reduction in 32.1% (9/28), and persistence in 3.6% (1/28). Radiological follow-up (50 lesions) demonstrated complete response in 96% and partial response in 4%. No major adverse events were reported according to CIRSE (≥ 4) or CTCAE (≥ 4) criteria. One SIR grade 3 vertebral fracture occurred without confirmed causal association to RGE. Subsequent surgery was required in 3.6% of lesions. Conclusion Although limited to small retrospective series, current evidence suggests that RGE sclerotherapy is a safe and effective minimally invasive option for selected benign bone lesions. Prospective comparative studies with longer follow-up are warranted.

Background/Objectives: Poiseuille’s law describes the influence of radius, length, viscosity, and pressure on the flow of Newtonian fluids. Although bone cement is a non-Newtonian, shear-thinning, and polymerizing material that does not comply with this law in any predictive or quantitative sense, its qualitative principles may offer a didactic framework for understanding factors that affect injectability during cementoplasty. The objective of this Technical Note is to provide an educational and conceptual interpretation of Poiseuille’s law as it relates to trocar selection, cement behavior, and procedural planning. Methods: This work presents theoretical calculations based on the r⁴/L component of Poiseuille’s equation, using manufacturer-specified internal radii for commonly used trocars. Relative flow rates were computed as r⁴/L ratios normalized to a 13-gauge, 15 cm trocar. Conceptual viscosity profiles illustrate qualitative differences among cements over time. A representative, fully anonymized clinical example is provided to illustrate the integration of these conceptual principles into practice. No experimental measurements were performed. Results: Theoretical calculations show that trocar radius has the strongest influence on theoretical flow, with an exponential effect (r⁴), whereas increasing trocar length proportionally reduces flow. Conceptual viscosity curves demonstrate the rapid rise in viscosity during polymerization and highlight the importance of timing and cement selection. The clinical example illustrates how trocar choice, access planning, and cement viscosity are adapted to lesion morphology and cortical integrity. Conclusions: Poiseuille’s law cannot model or predict bone cement behavior and has no procedural or clinical validity in cementoplasty. Its use in this Technical Note is strictly educational, providing a qualitative framework to illustrate general relationships between equipment characteristics, viscosity evolution, and resistance during injection, without offering clinical guidance or implying any impact on procedural planning, safety, or outcomes.